Traditional internal combustion engines include a cooling system in which water (or other coolant) is fed through the engine block and then through a radiator by a water pump to dissipate excess heat and to keep the engine temperature at an acceptable level. A traditional water pump may be sized to constantly provide a level of coolant flow that is adequate for peak operating conditions. Variable speed water pumps may be used to reduce the parasitic losses on the engine caused by the water pump when less than the peak level of coolant flow is needed to maintain the engine temperature within acceptable levels.
Though variable speed water pumps are known in general, what is needed is a variable speed water pump that is configured to respond to parameters other than engine oil temperature or coolant temperature in determining a control strategy.